Why Your Thoughts Are Not In Your Head

Your words do not get their meaning from your own mind alone. Two people with identical brain activity can mean completely different things because meaning is shaped by the world outside.

Think of two people imagining a glass of water. If one is on Earth and the other is on a twin planet where water is made of a different chemical substance, they are thinking about different things despite having identical brain states. This suggests that the environment acts as a partner in defining our concepts. We are literally tethered to our surroundings to give our language any real substance.